1. Technical Field
This invention relates to airport runway light support apparatus and methods. In one aspect, this invention relates to height and azimuth adjustable container apparatus and methods for embedded container light supports for airport runways and the alignment of their light fixtures. In one aspect, this invention relates to adjustable airport runway lights and to apparatus and methods for specialized, set-in-the-ground lighting systems utilized for the purpose of guiding pilots during their approach to an airport runway and during the landing and taxi of aircraft.
2. Background
Conventional lighting fixtures forming part of specialized, set-in-the-ground airport runway lighting systems are mounted on certain steel containers. The steel containers for these airport runway inset lights can be one-part or two-part and, sometimes, three-part containers and are set below the surface of runways, taxiways, and other aircraft ground traffic areas. The bottom sections of the containers are sometimes called shallow light bases. The top sections are called fixed-length extensions and are manufactured in different fixed lengths and diameters. Flat spacer rings are installed between the extensions and the lighting fixtures for providing further height and azimuth adjustments. These conventional steel containers, in addition to servings as bases for mounting the lighting fixtures, also serve as transformer housings and junction boxes to bring electrical power to the lighting fixtures.
In the installation of airport runway touchdown zone, centerline, and edge lighting systems, as well as in the construction or installation of taxiway centerline and edge lighting systems, and other lighting systems, these containers are embedded in the runway, taxiway, and other pavements at the time the runway and taxiway pavements are poured (concrete) or placed (bituminous). These containers, hereinafter referred to as embedded containers, vary in length and diameter. Conventional embedded containers provide an inverted flange at their top portion, which flange has a standard set of threaded holes to allow for the runway, taxiway, edge, and other light fixtures to be bolted onto them above the pavement surface, or to allow for the top section of the container to be bolted onto the bottom section, if it is a two-section container. A great majority of these existing, conventional containers are two section containers, bolted together at their inverted flanges. The light fixture then is bolted onto the top inverted flange of the top section of the two-section container. The top section of the two-section container is referred to as the fixed-length extension, which is part of the conventional embedded containers.
The top portions of the lighting fixtures are installed at a close tolerance, slightly above the pavement surface. Installations of the containers and their lighting fixtures are required on two different occasions. The first is when the runways, taxiways, and other aircraft ground traffic areas are built for the first time. The second is for resurfacing or repaving of the runways, taxiways, and other aircraft ground traffic areas. The latter is the most common, i.e., most frequent.
The light fixtures installed on the embedded containers, otherwise known as airport inset lights, have to be aligned with respect to each other in a precise, straight line on the horizontal plane known as azimuth correction, and their height has to be set within a fixed, strict tolerance measured from the pavement surface.
Each airport paving project may consist of installing hundreds or thousands of lighting fixtures and their airport inset light containers.
Runways, taxiways, and other aircraft ground traffic areas deteriorate with years of usage. This creates the need for resurfacing or repaving, i.e., replacing the asphalt of these ground surfaces. Repavement is a much more common, i.e., frequent, occurrence than the construction of new pavements.
When a runway, taxiway, or other aircraft ground traffic area is first built, or when upgrading or modernizing, or when maintenance projects require their resurfacing (repavement), the flanges on the embedded containers get buried under the pavement. This creates the need for height adjusting devices with flanges identical to those of the embedded containers to adapt the container up to the final surface and for the lighting fixtures to be installed and aligned above the payment. In many instances, this requires core-drilling the newly poured or placed pavement to reach down to the now buried top flange of the embedded container.
Depending on the lengths of the runways and taxiways, thousands of these embedded containers are affected, and a wide variety of height adjustments can be involved for each given size of embedded containers. In such an adjustment system, fixed-length extensions must be made available in many different lengths, so as to provide the many different gross height adjustments. A combination of one or more flat spacer rings, which are manufactured in thicknesses of 1/16, ⅛, ¼, and ½ inch (1.6,3.2, 6.3, and 12.7 millimeters, approximately), and other thicknesses, can be used to provide the final height.
These fixed-length extensions have one inverted flange on each end to bolt onto the embedded container, and then flat rings are added on top of the fixed-length extension top flange before the lighting fixture is bolted onto the flange.
The fixed-length extensions and the flat spacer rings must be individually ordered to the required length. This adjustment system makes for a difficult and tedious conventional installation procedure involving (1) field measurement of each individual fixed extension length and flat spacer ring required for every container (2) record keeping of all those field measurements and locations for ordering and verification; (3) ordering, receiving, and delivering to the field each size according to its location; and (4) frequently having to install more than one flat spacer ring to achieve the required height. The listed complications for the difficult conventional installation procedure are further magnified by the fact that the embedded containers are made in 4 different sizes: 10, 12, 15, and 16 inches (25.4, 30.5, 38.1, and 40.6 centimeters, approximately) in diameter.
These embedded containers below the pavement surface serve as light fixture bases. They also serve as transformer housings and junction boxes.